1. Field of the Invention
This invention relates to a process for producing a cover with a glass pane and electrical function elements.
2. Description of Related Art
Covers provided with electrical function elements for an opening in a motor vehicle roof or solid glass covers are known in various embodiments. For example, published European Patent Application EP 1 234 721 A2 discloses an adjustable cover which is provided with flat illumination elements. The illumination elements are, for example, electroluminescent (EL) films. The required layers (electrodes, EL layer, protective films, etc.) are applied in succession. If, in a transparent region of a motor vehicle roof, the intention is to control the transparency of the cover by applying a voltage, electrochrome (EC) elements are used. Examples of these electrochrome coatings are disclosed in German Patent DE 197 23 596 C1 which corresponds to U.S. Pat. No. 5,995,272 and in published German Patent Application DE 196 30 812 A1.
Alternative elements for controlling the transparency of transparent vehicle surfaces are liquid crystal (LCD) elements and SPD (suspended particle device) layers. One example of such a motor vehicle window system can be found in published German Patent Application DE 100 43 141 A1. If, for example, the cover of a sliding roof is intended to be used as a voltage source, solar elements of semiconductor materials are used. Examples are given in published German Patent Application DE 43 23 140 A1 and published French Patent Application FR 2 673 768 A1 and corresponding U.S. Pat. No. 5,213,626. If the intention is to prevent a glass cover for closing an opening in a motor vehicle roof from shattering and clearing the opening in an accident, tear-resistant and scratch-proof shatter prevention films can be cemented onto the bottom of the pane of the glass cover. One example of this can be found in published German Patent Application DE 101 51 156 A1 corresponding to commonly owned, co-pending U.S. patent application Ser. No. 10/485,711.
In these known possibilities for integration of electrical function elements into covers for motor vehicle roofs, the successive build-up of the layer combination during the production of the cover is a disadvantage. Since the layer combination, for example, in a glass cover in the simplest case is composed of the glass, an adhesive layer, the function element, another adhesive layer and then a protective film, the structure is complex, and moreover, entails the risk of dirt inclusions or lamination faults. This results in high production costs. In addition, combinations of various function elements can only be produced with difficulty in this way. In many cases, for example, in EC coatings, a spherically arched pane must be coated using a vacuum process; this means higher costs for smaller numbers. Known EL films, due to the brittleness of the ITO layers used for the electrodes can only be processed in large radii.